PORTLAND, Ore. – At a darkened train station, the teenager and the purported jihadi pulled into a quiet lot where months of planning were to culminate in this: a plot to kill thousands at a Portland Christmas tree-lighting ceremony.

"You know what to do," the man said to the teenager, breathing heavily. "O Lord, O Lord, O Lord."

"Ready," the teenager said. "Alhamdulillah." Praise be to God.

They were 14 blocks northeast of this city's busy tree-lighting ceremony two years ago on Nov. 26, 2010. On Friday, they found themselves across a federal courtroom from each other where the man — who Mohamed Mohamud would learn was an undercover FBI agent — testified against the now 21-year-old and a jury listened to a recording of the moments leading up to his arrest.

The recording crackles as the FBI agent reads out numbers and the teenager punches them into his black disposable Nokia cellphone. He then apparently encounters an error.

"Dial it again," the man said, words that were in fact the cue for his fellow agents. Mohamud dialed again and waited for the explosion.

Instead: "FBI, FBI, FBI! Get down!"

The agent, whose cover name was "Hussein," had told Mohamud the number he dialed was connected to a cell phone that would set off six 55-gallon drums filled with diesel fuel in a van parked next to the tree-lighting. The explosion, "Hussein" told him, would destroy two blocks in any direction.

Mohamud's defense team doesn't dispute the sequence of events, nor that their client intended to kill thousands of people at the tree-lighting ceremony.

But the path by which he reached that point is the substance of the defense's claim that Mohamud was entrapped. The entrapment defense has been launched, unsuccessfully, in several post-9/11 terrorism sting operations like the one that targeted Mohamud.

He came to the FBI's attention, agents testified, when he kept up email contact with a Saudi Arabian man suspected by Interpol of terrorism.

Without the bureau's intervention, prosecutors say, the already-radicalized Mohamud would almost certainly have found a way to reach al-Qaida or one of its affiliates and commit an act of terror in the U.S.

Nonsense, Mohamud's attorneys said in opening statements and cross-examinations of prosecution witnesses. He was a 17-year-old when his emails were identified by the FBI, a teenager with grand but muddled ambitions of achieving some sort of fame in the Islamic world.

If anyone radicalized him, his attorneys attest, it was the undercover FBI agents who convinced him they were members of al-Qaida that had chosen him as a promising recruit.

Jurors had by Friday heard the details of the undercover sting operation and testimony from the men who led it. "Youssef," another undercover agent testifying under a pseudonym, said he encountered an angry young man at the outset of the sting on July 30, 2010.

But "Youssef" said he didn't believe Mohamud was truly capable of violence. Not yet. It wasn't until an August 2010 meeting in which Mohamud picked the tree-lighting ceremony as a target that "Youssef" became concerned that he was dealing with a potentially dangerous person.

After that meeting on Aug. 19, 2010, at least one agent or handler left his or her recorder running. The agents were heard saying it was "fantastic" that Mohamud had identified a "sexy" terrorist target, according to transcripts of the meeting quoted by Mohamud's defense team.

That plays in direct contrast to the FBI agents' assertions that they kept hoping Mohamud would turn his back to violence and instead choose a different option offered by the agents: Pray five times daily, get an engineering degree, fundraise for al-Qaida.

Instead, they say, he insisted on becoming "operational," at first even asking to be a martyr before the agents talked him out of it. It was a theme that they said continued throughout the sting: Agents offered peaceful options, Mohamud repeatedly chose violence.

Even in the final minute of the final hour of the final day, parked in the train station lot, "Hussein" said Mohamud could have walked away.

"Was there any hesitation on his part?" asked prosecutor Pam Holsinger on Friday.

"None," Hussein said.

Holsinger paused.

"If he saw (the bomb) and said he didn't want to..." Holsinger said.

"If he did not dial the number," the agent said, "the directive was for us to drive him home."